ES2659797T3 - Heavy fuel oil type production process from a heavy hydrocarbon load using a separation between the hydrotreatment stage and the hydrocracking stage - Google Patents

Abstract

Process for treating a heavy hydrocarbon charge that has a sulfur content of at least 0.5% by weight, an initial boiling temperature of at least 350ºC and a final boiling temperature of at least 450ºC, which allows obtaining least one liquid hydrocarbon fraction that has a sulfur content less than or equal to 0.5% by weight, said liquid hydrocarbon fraction is a heavy fuel oil type fuel that can optionally be converted into a marine fuel, said process comprising the following successive stages: a) a fixed-bed hydrotreatment stage, in which the hydrocarbon and hydrogen feed are contacted over a hydrotreatment catalyst, b) a separation stage of the effluent obtained at the end of stage (a) of hydrotreatment in al least one light fraction and at least one heavy fraction, c) a hydrocracking stage of at least part of the heavy fraction of the effluent resulting from the stage (b), taken alone or mixed with other residual or fluidizing cuts, in at least one reactor that works in hybrid mode, that is, that works in a bubbling bed with a supported catalyst, in the form of extrudates whose diameter is between 0 .8 and 1.2 mm, associated with a "disperse" catalyst made up of very fine catalyst particles, which have a size between 0.1 and 100 micrometers, which constitute a suspension with the liquid hydrocarbon phase to be treated, d) a separation stage of the effluent resulting from stage (c) to obtain at least one light fraction and at least one heavy fraction, e) a sediment treatment stage that allows reducing the sediment content of the heavy fraction resulting from stage of separation d), f) a final separation stage of the effluent of treatment stage e) to obtain said liquid hydrocarbon fraction with a reduced content of sediments (that is, less than 0.1% in p that), process in which the hydrocracking stage is carried out with the following operating conditions: - a partial pressure of hydrogen that varies from 2 to 35 MPa, and preferably from 10 to 25 MPa, - a temperature between 330 ºC and 550 ºC, preferably 350 ºC to 500 ºC, even more preferably between 370 ºC and 480 ºC, - an hourly space velocity (VEH of the reactor, ratio between the volumetric flow rate of the load and the volume of the reactor) between 0.1 and 10 h-1, preferably 0.1 h to 5 h-1 and more preferably between 0.1 and 2 h-1, - an hourly space velocity of "bubbling bed catalysts" for bubbling or hybrid bed reactors between 0.1 and 5 h-1, preferably 0.1 h to 3 h-1 and more preferably between 0.1 and 1 h-1, the VEH of the "bubbling bed catalyst" is defined as the ratio between the volumetric flow rate of load in m3/h and the volume in m3 of the catalyst in the bubbling bed at rest, that is, when or the rate of expansion of the bubbling bed is zero, - a content of metallic compounds in the catalysts used in the hybrid bed between 0 and 10% by weight, preferably between 0 and 1% by weight, said content being expressed as a percentage in weight of metallic elements of group VIII and/or group VIB, - a hydrogen/charge ratio between 50 and 5,000 Nm3/m3, preferably between 100 and 1,500 Nm3/m3, with a still preferred range between 500 and 1,300 Nm3/ m3.

Description

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Another part of the fraction (194) of atmospheric waste can be sent to another procedure (hydrocracking or FCC or hydrotreatment).

A variant not shown but close to the scheme in Figure 2 may consist of not using the system of

5 fractionation (70) or dilute the liquid fraction (56) resulting from the cold separator (52). The liquid fraction (56) is then sent to the hydrocracking section optionally by means of a pump mixed with the heavy fraction (48) resulting from the separator (44).

It does not transcend from the field of the invention, that the separation stage is with or without decompression, with variants of the hydrocracking section from the moment this hydrocracking section consists of at least one hybrid type hydrocracking reactor.

These variations of the invention are especially included for the hydrocracking section instead of two hybrid bed reactors (98) and (102):

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a bubble bed type hydrocracking reactor followed by a hybrid bed type hydrocracking reactor

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a hybrid bed type hydrocracking reactor followed by a hybrid bed type hydrocracking reactor

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a single bed hybrid type hydrocracking reactor.

In the variants referring to the type of hydrocracking reactors described above, it is also possible to interleave an interetapa separator that allows the elimination of at least one gas fraction between two hydrocracking reactors.

Comparative example according to the prior art and according to the invention The following example illustrates the invention without limiting its scope.

A vacuum residue (Oural RSV) containing 87.0% by weight of compounds boiling at a temperature above 520 ° C, with a density of 9.5 ° API and a sulfur content of 2.72% by weight was treated .

30 The load was subjected to a stage a) of fixed bed hydrotreatment that includes two interchangeable reactors. The operating conditions are given in table 1.

Table 1: Operating conditions of stage a) of fixed bed hydrotreatment

HDM and HDS catalysts

NiCoMo on alumina

Temperature (° C)

370

H2 partial pressure (MPa)

fifteen

VEH (h-1, Sm3 / h recent load / m3 of catalyst in fixed bed)

 0.18

HC / H2 input into the bed section outside the H2 consumption (Nm3 / m3 of recent load)

1,000

The hydrotreatment effluent is then subjected to a separation step b) as described in Figure 1 and which allows recovering a gas fraction and a heavy fraction containing a majority of compounds boiling at more than 350 ° C (fraction 350 ºC +).

40 The heavy fraction (fraction 350 ° C +) is then treated according to two schemes:

a) in a hydrocracking stage c) comprising two successive reactors in bubbling beds (not in accordance with the prior art).

B) in a hydrocracking stage c) comprising two successive reactors in bubbling beds with the addition of a dispersed catalyst which is carried out according to a "hybrid" mode (according to the invention).

The operating conditions of hydrocracking stage c) are given in table 2.

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Claims (1)

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